1. Field of the Invention
Embodiments of the invention relate to a touch sensor integrated type display device capable of recognizing a user's touch, and more particularly to a touch sensor integrated type display device capable of increasing sensitivity of a touch sensor by reducing a change amount of a capacitance generated by touch driving electrodes.
2. Discussion of the Related Art
In recent years, various input devices such as a keyboard, a mouse, a joystick, and a digitizer have been used to construct interfaces between users and home appliances or information telecommunication devices. However, when the user makes use of these input devices, user's dissatisfaction increases because the user is required to know how to use the input devices and the input devices occupy space. Therefore, a convenient and simple input device that can reduce erroneous operation is required. In response to this demand, a touch sensor for enabling the user to input information by directly touching the screen with his or her hand or a pen was suggested.
The touch sensor has a simple configuration capable of reducing erroneous operations. The user can also perform an input action without using a separate input device, and can quickly and easily manipulate a device through contents displayed on the screen. Accordingly, the touch sensor has been applied to various display devices.
The touch sensor used in the display devices may be classified into an add-on type touch sensor and an on-cell type touch sensor. The add-on type touch sensor is configured such that the display device and the add-on type touch sensor are individually manufactured and then the add-on type touch sensor is attached to an upper substrate of the display device. The on-cell type touch sensor is configured such that components constituting the on-cell type touch sensor are directly formed on the surface of the upper glass substrate of the display device.
There is a problem that a thickness of the display device increases because the add-on type touch sensor has the structure in which the add-on type touch sensor is mounted on the display device. Further, the visibility of the display device is reduced because of a reduction in brightness of the display device due to the increased thickness.
On the other hand, the on-cell type touch sensor shares the glass substrate with the display device because the on-cell type touch sensor has the structure in which the on-cell type touch sensor is formed on the surface of the glass substrate of the display device. Therefore, a thickness of the display device using the on-cell type touch sensor is less than a thickness of the display device using the add-on type touch sensor. However, the entire thickness of the display device using the on-cell type touch sensor increases because of a touch driving electrode layer, a touch sensing electrode layer, and an insulating layer for insulating the touch driving electrode layer and the touch sensing electrode layer which constitute the on-cell type touch sensor.
Accordingly, there is a need for a touch sensor integrated type display device capable of solving the problems of the above-described kinds of touch sensors.